Dentists chair mask prototype

Two silicone tubes. Layered duct tape if most of the construction. Then epoxy putty (Milliput) to fashion something to fit your nostrils. There's going to at least need to be S, M and L for different noses.

Regular KN95 style FFP2 mask, with ear loops snipped off, then nearly stapled shut, then some duct tape over that:

The two pieces assembled and more duct tape to eliminate air leakage.

The PortaCount shows 98.6% PFE which is fantastic. 

I've no idea how long a person could close off their mouth airway and use this while the dentist is busy in there. All while holding it in one place using one hand - on the side of their face that is opposite to the dentist.

If course it is just a prototype as the intention is to have a 3D printable version.  There would be left and and right hand versions as septum sticks out eliminating some top/bottom mirror imaging for the nose part of this.